An Experimental Comparison Between Air-Assisted Injection System and High Pressure Injection System at 2-Stroke Engine

1995 ◽  
Author(s):  
Kum-Jung Yoon ◽  
Won-Tae Kim ◽  
Hyun-Sung Shim ◽  
Guee-Won Moon
Keyword(s):  
High Pressure ◽  
Injection System ◽  
Experimental Comparison ◽  
Pressure Injection ◽  
High Pressure Injection ◽  
Stroke Engine

A Comprehensive Thermodynamic Approach to Acoustic Cavitation Simulation in High-Pressure Injection Systems by a Conservative Homogeneous Two-Phase Barotropic Flow Model

2005 ◽  
Vol 128 (2) ◽  
pp. 434-445 ◽  
Author(s):  
Andrea E. Catania ◽  
Alessandro Ferrari ◽  
Michele Manno ◽  
Ezio Spessa
Keyword(s):  
High Pressure ◽  
Wave Propagation ◽  
Flow Model ◽  
Acoustic Cavitation ◽  
Injection System ◽  
Pure Liquid ◽  
Two Phase ◽  
Pressure Injection ◽  
Barotropic Flow ◽  
High Pressure Injection

A general conservative numerical model for the simulation of transmission-line unsteady fluid dynamics has been developed and applied to high-pressure injection systems. A comprehensive thermodynamic approach for modeling acoustic cavitation, i.e., cavitation induced by wave propagation, was proposed on the basis of a conservative homogeneous two-phase barotropic flow model of a pure liquid, its vapor, and a gas, both dissolved and undissolved. A physically consistent sound speed equation was set in a closed analytical form of wide application. For the pure-liquid flow simulation outside the cavitation regions, or in the absence of these, temperature variations due to compressibility effects were taken into account, for the first time in injection system simulation, through a thermodynamic relation derived from the energy equation. Nevertheless, in the cavitating regions, an isothermal flow was retained consistently with negligible macroscopic thermal effects due to vaporization or condensation, because of the tiny amounts of liquid involved. A novel implicit, conservative, one-step, symmetrical, and trapezoidal scheme of second-order accuracy was employed to solve the partial differential equations governing the pipe flow. It can also be enhanced at a high-resolution level. The numerical model was applied to wave propagation and cavitation simulation in a high-pressure injection system of the pump-line-nozzle type for light and medium duty vehicles. The system was relevant to model assessment because, at part loads, it presented cavitating flow conditions that can be considered as severe, at least for a diesel injection system. The predicted time histories of pressure at two pipe locations and of injector needle lift were compared to experimental results, substantiating the validity and robustness of the developed conservative model in simulating acoustic cavitation inception and desinence with great accuracy degree. Cavitation transients and the flow discontinuities induced by them were numerically predicted and analyzed.

A Comprehensive Thermodynamic Approach to Acoustic Cavitation Simulation in High-Pressure Injection Systems by a Conservative Homogeneous Barotropic-Flow Model

2003 ◽  
Author(s):  
Andrea E. Catania ◽  
Alessandro Ferrari ◽  
Michele Manno ◽  
Ezio Spessa
Keyword(s):  
High Pressure ◽  
Wave Propagation ◽  
Numerical Model ◽  
Acoustic Cavitation ◽  
Injection System ◽  
Thermodynamic Approach ◽  
Pure Liquid ◽  
Model Assessment ◽  
Pressure Injection ◽  
High Pressure Injection

A general conservative numerical model for simulation of transmission-line unsteady fluid-dynamics has been developed and applied to high-pressure injection systems. A comprehensive thermodynamic approach for modeling acoustic cavitation, i.e. cavitation induced by wave propagation, was proposed on the basis of a homogeneous barotropic mixture model of a pure liquid in equilibrium with its vapor and a gas, both dissolved and undissolved. For the pure liquid flow simulation outside the cavitation regions, or in the absence of these, temperature variations due to compressibility effects were taken into account, for the first time in injection system simulation, through a thermodynamic state equation which was derived from energy considerations. Nevertheless, in the cavitation regions, an isothermal flow was retained which is consistent with negligible thermal effects due to vaporization because of the tiny amounts of liquid involved. A novel implicit, conservative, one step, symmetrical and trapezoidal scheme of the second-order accuracy was applied to solve the hyperbolic partial differential equations governing the pipe flows. It can also be enhanced at a high-resolution level. The numerical model was applied to wave propagation and cavitation simulation in a high-pressure injection system of the pump-line-nozzle type for light and medium duty vehicles. The system was of relevance to the model assessment because it presented severely cavitating flow conditions. The predicted pressure time histories at two pipe locations and injector needle lift were compared to experimental results, substantiating the validity and robustness of the developed conservative model in simulating cavitation inception and desinence with great degree of accuracy. Cavitation transients and the flow discontinuities induced by them were numerically analyzed and discussed.

Analysis of PWR RPV lower head SBLOCA scenarios with the failure of high-pressure injection system using MAAP5

2014 ◽  
Vol 77 ◽  
pp. 48-64 ◽  
Author(s):  
Wei Li ◽  
Xiaoli Wu ◽  
Yapei Zhang ◽  
Deyou Ma ◽  
Yongzheng Chen ◽  
...  
Keyword(s):  
High Pressure ◽  
Injection System ◽  
Pressure Injection ◽  
Lower Head ◽  
High Pressure Injection

scholarly journals A Drier Way To Clean Turbines

1998 ◽  
Vol 120 (03) ◽  
pp. 98-100 ◽  
Author(s):  
Michael Valenti
Keyword(s):  
High Pressure ◽  
Gas Turbines ◽  
Power Plants ◽  
Injection System ◽  
Offshore Platforms ◽  
Oil Platforms ◽  
Turbine Efficiency ◽  
Pressure Injection ◽  
Offshore Oil Platforms ◽  
High Pressure Injection

A high-pressure injection system that needs less water to clean gas turbines than conventional methods can reduce equipment maintenance costs for aircraft, offshore platforms, and power plants. Gas Turbine Efficiency (GTE) in Jarfalla, Sweden, has developed a high-pressure injection system that cleans turbines using atomized droplets and needs 90 percent less liquid than previous methods. With this technique, the operators of offshore oil platforms, power plants, refineries, and aircraft in several countries are reducing the purchase costs of new fluids, the disposal costs of spent cleaning fluids, and maintenance downtime. In creating their washing system, designers considered the differences in cleaning aviation and stationary engines. The turbine-washing system is available in mobile versions for aircraft engines and permanently installed versions, for the off-line cleaning of stationary turbines. GTE also designed two models to serve the very small and very large turbines. The GTE 30 A services the small turbines, ranging from 0.5 to 10 megawatts, that are used in industrial, power-generation, marine, and test-cell applications as well as turboprop aircraft, turbofan craft, and helicopters.

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